This invention relates to a quick coupler, and more particularly to a quick coupler for attaching and detaching an implement to and from a vehicle equipped with a lift arm and a tilt link.
An earthmoving vehicle equipped with a lift arm and a tilt link, such as a wheel loader, may accomplish a multitude of operations by attaching various work implements thereto. For instance, a loader equipped with a bucket can load and transport earth or the like, while a loader equipped with a fork can load and transport material on pallets or pipes. In this way, a single earthmoving vehicle may be used for multiple purposes, if such implements may be conveniently attached to the vehicle, as required.
Quick disconnect and attachment mechanisms for securing various implements to a vehicle are exemplified by U.S. Pat. Nos. 3,243,066, issued Mar. 29, 1966 to C. W. Gardner, et al.; 3,417,886, issued Dec. 24, 1968 to C. F. Stuart; 3,760,883, issued Sept. 25, 1973 to B. D. Birk; 3,818,551, issued June 25, 1974 to F. J. Coughran, Jr.; and 3,935,953, issued Feb. 3, 1976 to R. N. Stedman.
However, such prior mechanisms have been generally unsatisfactory from the standpoint that most have been excessively complex and costly in construction. For example, some of the mechanisms have been subject to misalignment problems so that the powerably moved pins on the hitch have had difficulty extending into the openings provided therefor in the rear portions of the implement. In still other cases, hydraulically powered jacks have been utilized, which jacks are expensive in construction and which jacks require an associated control system and extensive hydraulic conduits which are subject to damage and inadvertent leakage during operation of the implement. In still other cases, an excessive amount of wear occurs between the hitch and the hook members on the implement with the result that the connecting joints therebetween become loose and less positive in operation.